Exact budget equations for the second-order structure function tensor ⟨𝛿u$_{i}$𝛿u$_{j}$⟩, where 𝛿u is the difference of the i th fluctuating velocity component between two points, are used to study the two-point statistics of velocity fluctuations in inhomogeneous turbulence. The anisotropic generalised Kolmogorov equations (AGKE) describe the production, transport, redistribution and dissipation of every Reynolds stress component occurring simultaneously among different scales and in space, i.e. along directions of statistical inhomogeneity. The AGKE are effective to study the inter-component and multi-scale processes of turbulence. In contrast to more classic approaches, such as those based on the spectral decomposition of the velocity field, the AGKE provide a natural definition of scales in the inhomogeneous directions, and describe fluxes across such scales too. Compared to the generalised Kolmogorov equation, which is recovered as their half-trace, the AGKE can describe inter-component energy transfers occurring via the pressure–strain term and contain also budget equations for the off-diagonal components of ⟨𝛿u$_{i}$𝛿u$_{j}$⟩. ... mehr

Zugehörige Institution(en) am KIT |
Institut für Strömungsmechanik (ISTM) |

Publikationstyp |
Zeitschriftenaufsatz |

Publikationsdatum |
10.09.2020 |

Sprache |
Englisch |

Identifikator |
ISSN: 0022-1120, 1469-7645 KITopen-ID: 1000122221 |

Erschienen in |
Journal of fluid mechanics |

Band |
898 |

Seiten |
Art. Nr.: A5 |

Vorab online veröffentlicht am |
25.06.2020 |

Schlagwörter |
turbulence theory |

Nachgewiesen in |
Web of Science Scopus |

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